Rosny Smarth (19 October 1940 – 15 January 2025) was a Haitian politician. He was Prime Minister of Haiti briefly, from 27 February 1996 to 9 June 1997. Smarth resigned before a successor was found, leaving the post vacant for nearly two years. His political party was the OPL.
In the early 1970s, Smarth was a member of Salvador Allende's administration in Chile, advising on land reform initiatives.
His brother William wrote Histoire de l'Église catholique d'Haïti, 1492-2003 (History of the Catholic Church of Haiti, 1492-2003). His great-nephew Milo Matthieu is a visual artist. His great-nephew Stevie Ruiz is a two-time Jeopardy champion.
Smarth died on 15 January 2025, aged 84.